<template>
  <div>
    <header class="header">
      <!-- 头部的第一行 -->
      <div class="top">
        <div class="container">
          <div class="loginList">
            <p>尚品汇欢迎您！</p>
            <p v-if="!nickName">
              <span>请</span>
              <router-link to="/login" href="###">登录</router-link>
              <router-link to="/register" href="###" class="register"
                >免费注册</router-link
              >
            </p>
            <p v-else>
              <a>{{ nickName }}</a>
              <a class="register" @click="logout">退出登录</a>
            </p>
          </div>
          <div class="typeList">
            <a href="###">我的订单</a>
            <a href="###">我的购物车</a>
            <a href="###">我的尚品汇</a>
            <a href="###">尚品汇会员</a>
            <a href="###">企业采购</a>
            <a href="###">关注尚品汇</a>
            <a href="###">合作招商</a>
            <a href="###">商家后台</a>
          </div>
        </div>
      </div>
      <!--头部第二行 搜索区域-->
      <div class="bottom">
        <h1 class="logoArea">
          <router-link to="/home" title="尚品汇">
            <img src="./images/logo.png" alt="" />
          </router-link>
        </h1>
        <div class="searchArea">
          <form action="###" class="searchForm">
            <input
              type="text"
              id="autocomplete"
              class="input-error input-xxlarge"
              v-model="keyword"
            />
            <button
              class="sui-btn btn-xlarge btn-danger"
              @click="goSearch"
              type="button"
            >
              搜索
            </button>
          </form>
        </div>
      </div>
    </header>
  </div>
</template>

<script>

//辅助函数获取用户名字
import {mapState} from 'vuex';

export default {
  name: "Header",

  data() {
    return {
      keyword: "",
    };
  },

  methods: {
    // 搜索按钮回调函数
    goSearch() {
      // 跳转到搜索页面:编程式导航
      //路由跳转与传递参数
      //第一种写法:字符串写法
      //this.$router.push("/search?a=1&keyword="+this.keyword);
      //this.$router.push('/search/1/'+this.keyword)
      //this.$router.push('/search/'+this.keyword+'?a=1');

      //第二种写法:模板字符串
      //  this.$router.push(`/search/${this.keyword}?a=1`);

      //第三种写法:对象写法
      //this.$router.push({path:'/search'});//没有携带参数
      // this.$router.push({ path: "/search",query:{a:1,keyword:this.keyword}});//携带query参数
      //路由组件传递参数:两个P犯冲
      // this.$router.push({path:'search',query:{keyword:this.keyword,value:'我是谁'}})
      //  this.$router.push({name:'search',params:{keyword:this.keyword,a:22}})

      //测试面试题第一题:params可以传递也可以不传递 ?????????????
      // this.$router.push({name:'search',params:{keyword:"我爱你塞北的大雪"}});

      //测试面试题第二题:
      //如果params参数可以传递也可以不传递[万万不能传递空串，导致URL发生错误]
      //this:组件实例VC
      //this.$router 实质VueRouter类实例
      //this.$router.push  实质VueRouter.prototype方法
      //VueRouter.prototype.push执行一次:返回是一个Promise对象，足以验证确实用到Promise技术
      //Promise对象:pending|成功|失败
      //第一种解决方案
      //这种写法可以实现路由跳转与传递参数
      //   this.$router.push({name:'search',params:{keyword:this.keyword||undefined}},()=>{},(error)=>{})

      let locations = {
        name: "search",
        params: { keyword: this.keyword || undefined },
      };
      // 如果query参数有:携带,没有携带空对象
      locations.query = this.$route.query;
      this.$router.push(locations);

      //   this.$router.push({name:'search',params:{keyword:this.keyword||undefined}},()=>{},()=>{});

      //底下代码可以验证:push里面this需要保证是VueRouter类的实例才可以路由跳转与传递参数
      //如果push方法this变为undefined会报错：undefined.history报错
      // let push   = this.$router.push;
      // push({name:'search',params:{keyword:this.keyword||undefined}},()=>{},(error)=>{});
    },
       //退出登录按钮的回调
    logout(){
      //派发action,通知vuex情况数据
      this.$store.dispatch('logout');
    }
  },
  mounted() {
    //监听removeKeyword事件
    this.$bus.$on("clearKeyword", () => {
      this.keyword = "";
    });
  },
  computed:{
     ...mapState({
         nickName:state=>state.user.nickName
     })
  }
};
</script>

<style lang="less" scoped>
.header {
  & > .top {
    background-color: #eaeaea;
    height: 30px;
    line-height: 30px;

    .container {
      width: 1200px;
      margin: 0 auto;
      overflow: hidden;

      .loginList {
        float: left;

        p {
          float: left;
          margin-right: 10px;

          .register {
            border-left: 1px solid #b3aeae;
            padding: 0 5px;
            margin-left: 5px;
          }
        }
      }

      .typeList {
        float: right;

        a {
          padding: 0 10px;

          & + a {
            border-left: 1px solid #b3aeae;
          }
        }
      }
    }
  }

  & > .bottom {
    width: 1200px;
    margin: 0 auto;
    overflow: hidden;

    .logoArea {
      float: left;

      .logo {
        img {
          width: 175px;
          margin: 25px 45px;
        }
      }
    }

    .searchArea {
      float: right;
      margin-top: 35px;

      .searchForm {
        overflow: hidden;

        input {
          box-sizing: border-box;
          width: 490px;
          height: 32px;
          padding: 0px 4px;
          border: 2px solid #ea4a36;
          float: left;

          &:focus {
            outline: none;
          }
        }

        button {
          height: 32px;
          width: 68px;
          background-color: #ea4a36;
          border: none;
          color: #fff;
          float: left;
          cursor: pointer;

          &:focus {
            outline: none;
          }
        }
      }
    }
  }
}
</style>
